Ported from quirc.
Example
// open the image from disk
let img = open.unwrap;
// convert to gray scale
let img_gray = img.into_luma;
// create a decoder
let mut decoder = default;
// identify all qr codes
let codes = decoder.identify;
for code in codes
CLI Example
$ cargo build --release --example qrtest
$ qrtest <path-to-image>